import Vue from 'vue';
import Router from 'vue-router';
import Login from '@/views/Login';
import NotFound from '@/views/404';
import Home from '@/views/Home';
import Intro from '@/views/Intro/Intro';
import api from '@/service/api';
import store from '@/store';
import {
  getIFramePath,
  getIFrameUrl
} from '@/utils/iframe';

Vue.use(Router);

const router = new Router({
  routes: [
    {
      path: '/',
      name: '首页',
      component: Home,
      children: [
        {
          path: '',
          name: '系统介绍',
          component: Intro,
          meta: {
            icon: 'fa fa-home fa-lg',
            index: 0
        }
        }
      ]
    },
    {
      path: '/login',
      name: '登录',
      component: Login
    },
    {
      path: '/404',
      name: 'notFound',
      component: NotFound
    }
  ]
});

router.beforeEach((to, from, next) => {
  // 登录界面登录成功之后，会把用户信息保存在会话
  // 存在时间为会话生命周期，页面关闭即失效。
  let userName = sessionStorage.getItem('user');
  if (to.path === '/login') {
    // 如果是访问登录界面，如果用户会话信息存在，代表已登录过，跳转到主页
    if (userName) {
      next({
        path: '/'
      });
    } else {
      next();
    }
  } else {
    if (!userName) {
      // 如果访问非登录界面，且户会话信息不存在，代表未登录，则跳转到登录界面
      next({
        path: '/login'
      });
    } else {
      // 加载动态菜单和路由
      addDynamicMenuAndRoutes(userName, to);
      next();
    }
  }
});

/**
 * 加载动态菜单和路由
 */
function addDynamicMenuAndRoutes(userName, to) {
  // 处理 IFrame 嵌套页面
  handleIFrameUrl(to.path)
  if (store.state.app.menuRouteLoaded) { // 动态菜单和路由已经存在.
    return
  }
  api.menu.findNavTree({
    'userName': userName
  }).then(res => {
    // 添加动态路由
    let dynamicRoutes = addDynamicRoutes(res.data);
    // 处理静态组件绑定路由
    router.options.routes[0].children = router.options.routes[0].children.concat(dynamicRoutes);
    router.addRoutes(router.options.routes);
    // 保存加载状态
    store.commit('menuRouteLoaded', true);
    // 保存菜单树
    store.commit('setNavTree', res.data);
  }).then(() => {
    api.user.findPermissions({
      'name': userName
    }).then(res => {
      // 保存用户权限标识集合
      store.commit('setPerms', res.data);
    })
  });
}

/**
 * 处理IFrame嵌套页面
 */
function handleIFrameUrl(path) {
  // 嵌套页面，保存iframeUrl到store，供IFrame组件读取展示
  let url = path
  let length = store.state.iframe.iframeUrls.length
  for (let i = 0; i < length; i++) {
    let iframe = store.state.iframe.iframeUrls[i]
    if (path != null && path.endsWith(iframe.path)) {
      url = iframe.url
      store.commit('setIFrameUrl', url)
      break
    }
  }
}

/**
 * 添加动态(菜单)路由
 * @param {*} menuList 菜单列表
 * @param {*} routes 递归创建的动态(菜单)路由
 */
function addDynamicRoutes(menuList = [], routes = []) {
  var temp = [];
  for (var i = 0; i < menuList.length; i++) {
    if (menuList[i].children && menuList[i].children.length >= 1) {
      temp = temp.concat(menuList[i].children);
    } else if (menuList[i].url && /\S/.test(menuList[i].url)) {
      menuList[i].url = menuList[i].url.replace(/^\//, '');
      // 创建路由配置
      var route = {
        path: menuList[i].url,
        component: null,
        name: menuList[i].name,
        meta: {
          icon: menuList[i].icon,
          index: menuList[i].id
        }
      };
      let path = getIFramePath(menuList[i].url);
      if (path) {
        // 如果是嵌套页面, 通过iframe展示
        route['path'] = path;
        route['component'] = resolve => require([`@/views/IFrame/IFrame`], resolve);
        // 存储嵌套页面路由路径和访问URL
        let url = getIFrameUrl(menuList[i].url);
        let iFrameUrl = {
          'path': path,
          'url': url
        };
        store.commit('addIFrameUrl', iFrameUrl);
      } else {
        try {
          // 根据菜单URL动态加载vue组件，这里要求vue组件须按照url路径存储
          // 如url="sys/user"，则组件路径应是"@/views/sys/user.vue",否则组件加载不到
          let array = menuList[i].url.split('/');
          let url = '';
          for (let i = 0; i < array.length; i++) {
            url += array[i].substring(0, 1).toUpperCase() + array[i].substring(1) + '/';
          }
          url = url.substring(0, url.length - 1);
          route['component'] = resolve => require([`@/views/${url}`], resolve);
        } catch (e) {
          // do nothing.
        }
      }
      routes.push(route);
    }
  }
  if (temp.length >= 1) {
    addDynamicRoutes(temp, routes);
  } else {
    //  console.log('动态路由加载...')
    //  console.log(routes)
    //  console.log('动态路由加载完成.')
  }
  return routes;
}

export default router;